During the honing of bores, the working parts, normally designed as honing sticks, of the axially oscillating and rotationally driven honing tool are held so as to press against the bore wall. The conventional honing machine includes a feed mechanism which, after the tool is moved into the bore, moves the honing sticks radially toward the bore wall and produces contact pressure during the machining. The feed mechanism can be actuated hydraulically or mechanically. In hydraulic feed systems a constant feed force is produced. With mechanical feed systems, a certain feed displacement is predetermined. In this case, the feed force depends on the mechanical system and, in known processes, does not control the machining.
The feed force is concentrated on the particular bearing surface of the honing sticks at the bore wall. If this bearing surface decreases during machining, the pressure of the honing sticks per unit area increases. The rigidity of the feed system does not allow the honing sticks to give way.
A reduction in the bearing surface and, thus, an increased pressure per unit area results, for example, in regions of recesses and apertures in the bore wall, and also at the ends of the bore, since the honing sticks at these locations move with part of their lengths out of the bore before they are moved in again by stroke reversal of the honing tool. In blind-end bores and stepped bore walls there is also a narrowing of the bore at its inner limit, which likewise leads to an increased pressure per unit area. Differences in the pressure per unit area which occur during machining reduce the quality of the machined surface and lead to geometric inaccuracies in the workpiece. In addition, this results in non-uniform wear, particularly pronounced at certain locations, of the honing sticks, which frequently must be dressed for this reason.